11721226591 has 2 divisors, whose sum is σ = 11721226592. Its totient is φ = 11721226590.

The previous prime is 11721226547. The next prime is 11721226619. The reversal of 11721226591 is 19562212711.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 11721226591 - 2¹⁹ = 11720702303 is a prime.

It is a zygodrome in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 11721226591.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11721226541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5860613295 + 5860613296.

It is an arithmetic number, because the mean of its divisors is an integer number (5860613296).

Almost surely, 2^11721226591 is an apocalyptic number.

11721226591 is a deficient number, since it is larger than the sum of its proper divisors (1).

11721226591 is an equidigital number, since it uses as much as digits as its factorization.

11721226591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15120, while the sum is 37.

The spelling of 11721226591 in words is "eleven billion, seven hundred twenty-one million, two hundred twenty-six thousand, five hundred ninety-one".